We will administer the North American Spine Society (NASS) Lumbar Spine Outcome Assessment to patients before treatment and at followup visits to assess their physical functioning. We will also use the NASS questionnaire to collect demographic and lifestyle information at baseline and to assess patient expectations regarding treatment and level of satisfaction with the treatment during the followup period. We will do a physical examination and administer the patient-reported questionnaire prior to surgery and at 1, 3, 6, and 12 months after surgery. We will obtain magnetic resonance (MR) imaging of the lumbar spine 12 months after treatment.